This invention is directed generally to the material handling and container formation arts, and more particularly to a scroll strip conveyor system for directing a plurality of scroll strips from machinery wherein they are initially formed or sheared from sheet stock material to a hopper, and to a novel strip handling or feed mechanism for stacking the scroll strips in the hopper. Preferably an inspection station and ejector mechanism is provided along the conveyor for detecting and ejecting rejects among the scroll strips.
Scroll strips of the type handled by the system of the invention are generally well-known in the container fabrication arts. These scroll strips comprise flat, preformed sheets of metallic material which are formed from sheet stock and are later otherwise formed into generally circular can ends. These flat, preformed scroll strips are formed with an irregular peripheral configuration to maximize the number of can ends that may be punched or otherwise formed therefrom and to minimize the amount of waste material, and as such are difficult to handle and convey.
An important consideration in fabrication of can ends is avoiding defects such as small holes in the finished ends. It has been found to be more efficient to initially inspect the scroll strips for any such holes or other irregularities prior to the formation of can ends therefrom. Since a plurality of can ends, for example from six to eighteen or more can ends may be formed from each strip, it will be appreciated that inspection of the strips, prior to formation of individual can ends therefrom can save a great deal of production and inspection time.
An additional problem arises with respect to the process of conveying the scroll strips from the shearing machine to the press or other machinery which forms the individual can ends. Preferably, the aforementioned inspection and ejection of rejects should take place while the scroll strips are being conveyed between the respective machines. In this regard the apparatus of the present invention utilizes a conveyor belt having suitable optical inspection and rejection stations therealong. It will be recognized that the scroll strips must be individually conveyed in a flat condition along the conveyor belt to enable such visual inspection. However, it is normally desired to stack the scroll strips in a flat, abutting surface-to-surface condition to be fed to the can end forming press for further processing. Further, the infeed station for the forming press also must accommodate an adequate supply of strips, so that the press need not be stopped should the shearing machine have to be shut down for service or repair.
One problem which has arisen with respect to the foregoing process is that of reorienting the scroll strips from their flat end-to-end condition, individually travelling along the conveyor belt to a stacked condition within a hopper at the infeed station of the forming press. When the flat scroll strips are merely ejected from the conveyor belt directly into a hopper or other container, their orientation becomes difficult or impossible to control. That is, the scroll strips generally do not remain in an upright or vertically oriented, parallel condition, but rather tend to tip or fall over. Generally speaking the infeed hopper is angled downwardly so as to facilitate stacking of the scroll strips therein by gravity. This angle of the hopper encourages further tilting or canting of the strips, whereby individual strips may tip over, causing jamming of the hopper and preventing proper stacking of the scroll strips therein or introduction of further scroll strips thereto.